Glycerol monostearate (GMS) is known for its efficacy as a mold release agent for thermoplastic polycarbonate molding compositions. It has, however, been observed by the art-skilled that molecular weight degradation of polycarbonate, a result of transesterification with GMS, represents a drawback to the use of this mold release agent. Under the thermal conditions prevailing during molding the product of transesterification, GMS-carbonate, decomposes to yield carbon dioxide, which causes the molding defect known as splay. This defect is of major concern for the producers of optical storage devices, such as optical discs, not only because of the aesthetics aspect but also from the standpoint of replication of the imbedded information. The present invention addresses the above problem.
A compound conforming structurally to the inventive mold release agent has been disclosed in U.S. Pat. No. 5,145,751. The '751 document disclosed a magnetic recording medium which includes a non-magnetic substrate and a magnetic recording layer coated on the substrate. The layer comprises a compound embracing the present release agent.